Nest Building in The Weaver ants. (Oceophylla sps.) -An interesting process
The Weaver ants or Oceophylla sps are arboreal ants which colonise trees and weave intricate leaf nests. They are a group of highly social insects and play a significant role in pest management and in food and medicine. In several Asian countries oil for edible use is extracted from the larvae of Oecophylla ants. Only two species are currently recorded. Oceophylla smargadina is found in the tropical areas of South Asia to the northern parts of Australia. The other species Oceophylla longinoda is found in Africa. This clip relates to nests and nest building in O. smaragdina in trees of Polyalthea longifolia (commonly known as Ashok) and Neolamarckia cadamba (commonly known as Kadamb in Hindi) in road side plantations at Gomti Nagar, Lucknow, Uttar Pradesh, India in October 2025.
Nests are made out of weaving adjacent leaves or the leaves from adjacent trees and are very complex. They may form a closed-circuit structure with many diverse compartments. Nests, initially made of a single leaf, may grow in size with rising numbers and often be as big as a basketball. Additional nests may be glued to the parent nests. Colonies can be extremely large consisting more than a hundred nests and spanning across several trees.
The average population of ants in a nest ranges from about 2500 to 9000 depending on the size of the nest. A single colony may harbour as many as half a million workers. Once a colony is disturbed, the ants move to other places, holding larva in their mouths and rebuild the nests. They may also leave the nests when the nest leaves dry.
Occasionally many cooperative queens may be involved in colony reproduction. This is known as Pleometrosis’ as against ‘Haplometrosis’ where only a single mated queen is involved. A single nest may have different castes like the workers, drones and queens that help in building the nests.
The mated O. smaragdina queen starts a colony by laying the first batch of about 35 eggs under a leaf tree and taking care of the eggs until they hatch as worker ants. The worker ants are of two different sizes. Major workers may be about 8 to 10 mm in length and the minor workers just about half the size. The major workers forage for food, defend, maintain and expand the colony whereas the minor workers tend to stay within the nests where they care for the brood and milk, scale insects in or close to the nests. (For honey and other nutrition).
Workers perform specific functions like brood care, maintenance of nests, foraging, colony defence etc. Workers may explore an area for leaves which may be suitable for nest building and try to bring the leaves together in position with their strong mandibles and hind legs. This attracts other workers also. Nest building starts in earnest. Nest making is a very interesting cooperative activity. A beautiful mid-19th century description by Aitkins, a renowned naturalist mentions that, “Beginning at the point where the leaves were nearest each other, several ants hold of one with their jaws and of the other with their hind limbs and begin to pull. Where the distance is more, one ant seized one leaf and the second seized the first by the small of the back and pulled with its hind legs. A chain of up to five to six ants have been observed thus. The space between the leaves was spanned by a web of Ant fabric”. The edges of the leaves are fixed together by silk originating in the labial glands of the ant larvae. Once the leaf is in position, workers carry nearly mature larval weaver ants to the edges where the larva is manipulated to expel silk which binds the edges together. Some worker ants may also squeeze the fluid from unfertilised eggs of drone larva at the periphery for sealing the leaves. Once the near mature larvae have been positioned near the leaf edges, the workers who softly hold the larvae in their jaws, would tap the head the larva causing the Larva to expel strands of strong silk from the labial gland under the mouth. Each larva is then passed back and forth as a live dispenser to glue the edges of the leaves. Thousands of strands of larval silk are woven into sheets between the leaf edges of the nests creating a living water (weather) proof shelter. The nest is divided into chambers with the silk used to form passages within.
The ants can differentiate clearly between colony and non-colony mates. They are protective towards colony mates. Non colony mates are regarded as enemies. A single colony may support almost about half a million ants. The growth in numbers results in nests which are glued to the parent nest. The outer nests serve as defence. The oldest major workers, considered expendable because of their age, occupy the outer nests and defend the colony. The younger workers being fight worthy are retained in the inner nests. When the nest is disturbed the worker ants hold the larva individually and transport it to safe places.
©Srimaa Communication
Credits- Dr. Yashpal Singh, Mrs. Neena Singh, Mr. Manoj Kumar Yadav